There is quite a bit more, mainly annoying legalese. But where is the contact information? It is sitting on whois.namecheap.com (see the third line of output above):

$ whois -h whois.namecheap.com linux.com

I won’t print the output here, as it is very long, containing the Registrant, Admin, and Tech contact information. So what’s the deal, Lucille? Some registries, such as .com and .net are “thin” registries, storing a limited subset of domain data. To get complete information use the -h, or --host option, to get the complete dump from the domain’s Registrar WHOIS Server.

Most of the other top-level domains are thick registries, such as .info. Try whois blockchain.info to see an example.

Want to get rid of the obnoxious legalese? Use the -H option.

Digging DNS

Use the dig command to compare the results from different name servers to check for stale entries. DNS records are cached all over the place, and different servers have different refresh intervals. This is the simplest usage:

Take notice of the SERVER: 127.0.1.1#53(127.0.1.1) line near the end of the output. This is your default caching resolver. When the address is localhost, that means there is a DNS server installed on your machine. In my case that is Dnsmasq, which is being used by Network Manager:

Now we’re getting somewhere, as that is the address of my mobile hotspot, and I should have thought of that myself. I can log in to its weird little Web admin panel to see its upstream servers. A lot of consumer Internet gateways don’t let you view or change these settings, so try an external service such as What’s my DNS server?

These are interesting results. Let’s try the same run from a different Internet account, to see if any of these services are exposed to big bad Internet. You have a second network if you have a smartphone. There are probably apps you can download, or use your phone as a hotspot to your faithful Linux computer. Fetch the WAN IP address from the hotspot control panel and try again: